Elizabeth Warren speaks at an organizing event at Curate in Des Moines, Iowa.

In Council Bluffs, her mic went dead.

“No sound!” someone yelled.

“I know!” she hollered back with a laugh, before continuing her speech.

In Sioux City, she got a question about her claims to Native American ancestry.

“I'm glad you asked that question,” she replied. “I genuinely am.”

And in Des Moines, at the tail end of her three-day trip to Iowa, she nearly lost her voice.

“Bad news is I’ve caught a cold,” she said. “The good news is, nevertheless, I persist.”

Elizabeth Warren is, by her own admission, new to the rhythms of a national campaign. After taking questions at her first event of the weekend, the 69-year-old senator shot an uncertain glance at the emcee: “You gonna wrap this up or should I wrap this up?”

“I’m learnin’ how to do this as we go along,” she added with a laugh.

Warren’s 2020 presidential bid began on New Year’s Eve with the announcement of an exploratory committee but stumbled before it even started. For weeks last fall, she set up shop in early-voting states like Iowa and New Hampshire against the backdrop of negative headlines: Cherokee Nation leaders criticized her release of a DNA test, meant to explain her past claims to Native American heritage, as “inappropriate and wrong;” her hometown paper, the Boston Globe, suggested she step aside from the race because she had become too “divisive” a national political figure; and on the eve of her launch, a Massachusetts poll found that 56% of her own constituents didn’t want her in the race.

So when Warren hit the campaign trail this weekend, her team seemed poised, prepared even, for an uncertain week. They had taken risks, booking big venues they weren’t sure they could fill and making the decision to take randomly selected, unscreened questions from the audience at the end of each event. As it turned out, she answered difficult questions with easy confidence and more than filled the room at every stop on the trip, sending a small team of advance staffers to set up space for outdoor overflow crowds.

But when she boarded a Southwest flight for Iowa on Friday, there was one thing her team knew for certain: Elizabeth Warren can tell people exactly why she’s running.

It’s a question that should be at the center of any presidential campaign but one that candidates struggle with from the moment they jump into the race. Warren did in her first 72 hours what Hillary Clinton, the last Democratic nominee, failed to do for nearly two years on the campaign trail. When she made her first trip to Iowa in April of 2015, Clinton arrived with a well-established political machine and a crush of reporters and cameras — but when reporters asked her to expand on her reasons for getting in the race, she found herself reverting again and again to what was, at the time, an early mantra of her campaign: “Everyday Americans need a champion, and I want to be that champion.”

Kc McGinnis for BuzzFeed News

Elizabeth Warren takes a picture with Daniel and Molly Kueffer and their children at an organizing event in Sioux City, Iowa.

Warren’s answer was at the heart of every speech she gave, every question she answered, every part of her campaign launch. It begins with the story of her childhood, growing up in Oklahoma on the edge of the middle class; of a father (“my daddy”) who made a living selling paint and carpeting and housewares, who fell out of work when he almost died from a heart attack; of a mother (“my mama”) who walked to Sears in her best dress to get a job and pick up the slack; and of Warren, a girl who learned words like “mortgage” and “foreclosure” when she was still a girl (“heavy words for a kid,” she says) before putting herself through two public universities, before becoming a school teacher, a bankruptcy expert, a Harvard law professor, the creator of a new consumer protection agency, the senior senator from Massachusetts, and now a presidential candidate.

“For me, this is the fight of my life. I didn’t pick this because it poll-tested. I picked it because it picked me,” Warren tells crowds. “It picked me back in Oklahoma, when I began to understand that the way the rules are set up makes a big difference in whether or not you get a chance to succeed.” And from there, she says, she has spent her entire career, for decades, “on one central question: What’s happening to working families?”

“Understand, my mama worked hard. She was scared, she pulled herself up, and she worked hard. But a mama today can work just as hard as my mama did and not be able to take care of herself and her baby. And that’s because of rules set in a distant place.”

That place would be Washington, DC — target of disdain and determination for Warren on the campaign trail. “Whatever issue brought you here tonight” — immigration, health care, gun control, the economy, she says — “I guarantee it intersects with a Washington that is working for the rich and the powerful,” not working people.

Warren does not go out of her way to mention President Donald Trump or specific legislation such as Medicare for all, which she co-sponsored in the Senate alongside Sen. Bernie Sanders. Instead, she uses a tight 15-minute stump speech, followed by a brief Q&A with the crowd, with questions randomly selected via a Costco-sized roll of raffle-style tickets, to return again and again to what she refers to as “the fight of my lifetime,” narrated with a warmth that is part personal (“I actually want to start this with a little bit of a story,” she began in Council Bluffs), part college seminar (“Let’s really wonk out for a minute here,” she said in Des Moines, launching into a detailed aside about housing inequality and red-lining African American neighborhoods).

And Warren, known in Washington for her strict and strategic discipline with the press and as an operator in the Senate, did not deviate from that message through the trip. A question about her Native American heritage? “Ultimately what 2020 is going to be about is not about my family. It’s about the tens of millions of families across this country who just want a level playing field.” About her status as the first woman candidate in the race? “I’d never run for office before 2012. What pulled me in is what’s happening to working families.” About, a reporter asks at one stop, the fact that she talks about “the way things used to be and putting the country back—” Warren cut off the question entirely before he could even finish: “No, actually I don’t,” she said.

“I talk about how difficult the path has gotten for some families.”

When it comes to engaging with a field of rival Democrats, aides and supporters said this week, other groups are planning to help fill the void. One longtime Warren ally, an organization called the Progressive Change Campaign Committee, or PCCC, has already taken on an outside role. When the senator challenged other Democrats to “link arms” and promise not to take money from super PACs or self-fund their campaigns, PCCC began organizing supporters on Twitter to pressure other prospective candidates.

The question of how, exactly, to defeat Trump has troubled Democrats since it became clear to Hillary Clinton and her team that she would be facing the reality star in the 2016 general election. More than two years later, it’s still an open debate: “fight fire with fire,” or channel Michelle Obama’s words at the Democratic National Convention in 2016 — “When they go low, we go high”? For Warren, who is a frequent target of Trump tweets referring to the senator as “Pocahontas,” the answer seems to be something of a meeting point between the two: a “fighter,” aides say, capable of both compromise and empathy.

As Warren put it in Iowa, it’s a time to “dream big and fight hard.”

“One question that a lot of voters will ask is, ‘Do I understand a candidate’s core worldview on future issues that nobody anticipates yet?’” said PCCC cofounder Adam Green, who attended Warren’s events in Iowa with a “Warren Wing” pin affixed to his dress shirt. “Do we understand where they will come down? With Elizabeth Warren the answer is always yes. That will be true for a few others as well — but not everyone.”

In a nutshell, Warren told her first audience, “I’m in this fight because I am grateful. My daddy ended up as a janitor, and I had a chance to become a public school teacher, a college professor, and a United States senator. I am grateful to America down to my toes. I am grateful, but I am also determined. I am determined that we build an America where not just the children of rich people get a chance to build something, but where all of our children get a chance to build a real future.

“That’s what I'm in this fight for.”

Kc McGinnis for BuzzFeed News

Elizabeth Warren speaks at an organizing event at Curate in Des Moines, Iowa.

In the first week of Warren’s campaign, that fight began with a personal touch at its center and without the rigid formality of a more established political campaign.

At the end of the trip, an aide who had just joined the team was taken aback to see Warren cleaning the trash out of her own rental car. The senator, elected in 2012, is still new to politics, without the trappings of Secret Service or the guard of a lifelong public official.

As she wades through a crowd outside the venue, she won’t shake your hand. She’ll give you a hug — a big, full-contact hug. She’ll lift your daughter in the air with both arms. She’ll kneel down, knees bent, to talk to your son at eye level. “Hi, sweetie,” she told a young boy named Carter. “I’m glad you’re here — I need you in this fight.” After her speech, she’ll take four or five questions from the crowd. If she gets excited, she’ll keep going. (“Foreign policy!” she exclaimed at one point in Council Bluffs.) And when the emcee tells the audience that, schedule allowing, the senator will stick around for pictures after the event — and “see as many people as she can” — Warren will flatly correct him.

“No,” she said in Des Moines, “as many people as want to.”

The accessible approach left an impression on local Iowa strategists, who were also impressed by the crowds she drew — more than 1,000 in Des Moines — and the team’s decisions to spend the trip in more rural, conservative-leaning cities in western Iowa.

“If you’re a Democrat in western Iowa, you have to be a really strong Democrat,” said Troy Price, chair of the Iowa Democratic Party, citing a long list of losses in the area over the last few election cycles. “Some of the best activists and volunteers are there.”

Ahead of their inaugural trip, Warren’s camp announced that four veteran operatives would be joining their Iowa team. Democrats in the state anticipate that Emily Parcell, who most recently served as a direct mail consultant on Rep. Abby Finkenauer’s race in Iowa’s 1st Congressional District, will serve as a senior adviser alongside former Clinton aide Janice Rottenberg, who will fill a state director role. The two other strategists, Finkenauer campaign manager Kane Miller and former Sanders caucus director Brendan Summers, are expected to take on early-state jobs at Warren’s headquarters in Boston, where the team is still setting up an office space.

Warren, meanwhile, is planning her next trip — to New Hampshire.

When a reporter asked her why she decided to get in the race so early, thirteen months before the start of voting, Warren once again came back around to a familiar answer.

“I’m in this fight, and I don’t know anything to do except fight it,” she said.

“So there was no point in putting it off.”

Ruby Cramer is a politics reporter for BuzzFeed News and is based in New York.